345 research outputs found
Nurses\u27 Alumnae Association Bulletin, April 1955
Alumnae Notes
Annual Giving
Committee Reports
Digest of Alumnae Meetings
Graduation Awards - 1954
Legal Aspects of Nursing
Marriages
Necrology
New Arrivals
Physical Advances at Jefferson
President\u27s Message
School of Nursing Report
The Challenge of Neurosurgical Nursin
Understanding Silent Failures in Medical Image Classification
To ensure the reliable use of classification systems in medical applications,
it is crucial to prevent silent failures. This can be achieved by either
designing classifiers that are robust enough to avoid failures in the first
place, or by detecting remaining failures using confidence scoring functions
(CSFs). A predominant source of failures in image classification is
distribution shifts between training data and deployment data. To understand
the current state of silent failure prevention in medical imaging, we conduct
the first comprehensive analysis comparing various CSFs in four biomedical
tasks and a diverse range of distribution shifts. Based on the result that none
of the benchmarked CSFs can reliably prevent silent failures, we conclude that
a deeper understanding of the root causes of failures in the data is required.
To facilitate this, we introduce SF-Visuals, an interactive analysis tool that
uses latent space clustering to visualize shifts and failures. On the basis of
various examples, we demonstrate how this tool can help researchers gain
insight into the requirements for safe application of classification systems in
the medical domain. The open-source benchmark and tool are at:
https://github.com/IML-DKFZ/sf-visuals.Comment: Accepted at MICCAI 2
A Call to Reflect on Evaluation Practices for Failure Detection in Image Classification
Reliable application of machine learning-based decision systems in the wild
is one of the major challenges currently investigated by the field. A large
portion of established approaches aims to detect erroneous predictions by means
of assigning confidence scores. This confidence may be obtained by either
quantifying the model's predictive uncertainty, learning explicit scoring
functions, or assessing whether the input is in line with the training
distribution. Curiously, while these approaches all state to address the same
eventual goal of detecting failures of a classifier upon real-life application,
they currently constitute largely separated research fields with individual
evaluation protocols, which either exclude a substantial part of relevant
methods or ignore large parts of relevant failure sources. In this work, we
systematically reveal current pitfalls caused by these inconsistencies and
derive requirements for a holistic and realistic evaluation of failure
detection. To demonstrate the relevance of this unified perspective, we present
a large-scale empirical study for the first time enabling benchmarking
confidence scoring functions w.r.t all relevant methods and failure sources.
The revelation of a simple softmax response baseline as the overall best
performing method underlines the drastic shortcomings of current evaluation in
the abundance of publicized research on confidence scoring. Code and trained
models are at https://github.com/IML-DKFZ/fd-shifts
MedNeXt: Transformer-driven Scaling of ConvNets for Medical Image Segmentation
There has been exploding interest in embracing Transformer-based
architectures for medical image segmentation. However, the lack of large-scale
annotated medical datasets make achieving performances equivalent to those in
natural images challenging. Convolutional networks, in contrast, have higher
inductive biases and consequently, are easily trainable to high performance.
Recently, the ConvNeXt architecture attempted to modernize the standard ConvNet
by mirroring Transformer blocks. In this work, we improve upon this to design a
modernized and scalable convolutional architecture customized to challenges of
data-scarce medical settings. We introduce MedNeXt, a Transformer-inspired
large kernel segmentation network which introduces - 1) A fully ConvNeXt 3D
Encoder-Decoder Network for medical image segmentation, 2) Residual ConvNeXt up
and downsampling blocks to preserve semantic richness across scales, 3) A novel
technique to iteratively increase kernel sizes by upsampling small kernel
networks, to prevent performance saturation on limited medical data, 4)
Compound scaling at multiple levels (depth, width, kernel size) of MedNeXt.
This leads to state-of-the-art performance on 4 tasks on CT and MRI modalities
and varying dataset sizes, representing a modernized deep architecture for
medical image segmentation. Our code is made publicly available at:
https://github.com/MIC-DKFZ/MedNeXt.Comment: Accepted at MICCAI 202
Validation of full-wave simulations for mode conversion of waves in the ion cyclotron range of frequencies with phase contrast imaging in Alcator C-Mod
Mode conversion of fast waves in the ion cyclotron range of frequencies (ICRF) is known to result in current drive and flow drive under optimised conditions, which may be utilized to control plasma profiles and improve fusion plasma performance. To describe these processes accurately in a realistic toroidal geometry, numerical simulations are essential. Quantitative comparison of these simulations and the actual experimental measurements is important to validate their predictions and to evaluate their limitations. The phase contrast imaging (PCI) diagnostic has been used to directly detect the ICRF waves in the Alcator C-Mod tokamak. The measurements have been compared with full-wave simulations through a synthetic diagnostic technique. Recently, the frequency response of the PCI detector array on Alcator C-Mod was recalibrated, which greatly improved the comparison between the measurements and the simulations. In this study, mode converted waves for D-{superscript 3]He and D-H plasmas with various ion species compositions were re-analyzed with the new calibration. For the minority heating cases, self-consistent electric fields and a minority ion distribution function were simulated by iterating a full-wave code and a Fokker-Planck code. The simulated mode converted wave intensity was in quite reasonable agreement with the measurements close to the antenna, but discrepancies remain for comparison at larger distances.United States. Department of Energy (Grant DE-FG02- 94ER54235
RecycleNet: Latent Feature Recycling Leads to Iterative Decision Refinement
Despite the remarkable success of deep learning systems over the last decade,
a key difference still remains between neural network and human
decision-making: As humans, we cannot only form a decision on the spot, but
also ponder, revisiting an initial guess from different angles, distilling
relevant information, arriving at a better decision. Here, we propose
RecycleNet, a latent feature recycling method, instilling the pondering
capability for neural networks to refine initial decisions over a number of
recycling steps, where outputs are fed back into earlier network layers in an
iterative fashion. This approach makes minimal assumptions about the neural
network architecture and thus can be implemented in a wide variety of contexts.
Using medical image segmentation as the evaluation environment, we show that
latent feature recycling enables the network to iteratively refine initial
predictions even beyond the iterations seen during training, converging towards
an improved decision. We evaluate this across a variety of segmentation
benchmarks and show consistent improvements even compared with top-performing
segmentation methods. This allows trading increased computation time for
improved performance, which can be beneficial, especially for safety-critical
applications.Comment: Accepted at 2024 Winter Conference on Applications of Computer Vision
(WACV
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